Battery charger



FIG. 1 is a front elevational view of the battery charger showing my new design;

FIG. 2 is a left side elevational view thereof, the right side being a mirror image, but for the switch;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a perspective view thereof; and

FIG. 7 is a perspective view of a second embodiment of my new design. 

The ornamental design for a battery charger, substantially as shown and described. 